Measurement of high resolution HRTFs

In binaural synthesis (computer-generated 3D sound) two components are needed: a dry sound signal recorded in an anechoic room as well as transfer functions (HRTFs) for positions in space around a person to the eardrums. In order to generate a binaural signal these two components are convolved such that the directionally dependent HRTF filters are applied to the sound. Traditionally HRTFs have been measured with a low spatial resolution, since the measurement procedure is difficult and time-consuming. This results in that only a limited number of positions can be synthesized. I practice this problem is often solved by interpolating between these HRTFs, even though these filters do not necessarily resemble the HRTFs measured for the same directions. In this project a high precision measurement system has been constructed in order to measure the HRTFs of the artificial head VALDEMAR. The measurements have been made with a spatial resolution of two degrees on the whole sphere. The result is a high resolution filter set that can be used in the implementation of binaural synthesis, as well as in analyses of the directionally dependent structures in the characteristics of human directional hearing. Supportet by STVF/FTP.